Error while adding test complete project to version control

Ah... a nicely elaborate error message :-) 

I'm guessing that something happened within SVN that was not verbose in it's communication back to the call within TestComplete.  However.... hard to tell.

An error like this would probably be best explored with a SmartBear employee.  Try using https://support.smartbear.com/message/?prod=TestComplete

Of course, if someone else here has encountered this error before, I'm sure they can help.  But you might get a better response from the actual customer care staff.